The present invention relates to a cylinder apparatus for brakes, and more particularly, to a cylinder apparatus for brakes capable of simplifying an assembly process thereof, and preventing a noise generating phenomenon.
In general, a brake for a vehicle is provided to reduce the speed of the vehicle or maintain the vehicle in a stably stopped state. While driving the vehicle, a driver frequently manipulates the brake to adjust the speed of the vehicle or maintain the vehicle in a temporarily stopped state. When the vehicle is parked or stopped for a long time, the brake makes it possible for the vehicle to remain stably parked.
The brake may include a brake pedal configured to receive a brake manipulating force from the driver, a booster configured to amplify the force of manipulating the brake pedal using a negative pressure provided from an intake system of an engine, a master cylinder configured to generate a high brake pressure by the operation of the booster, and a wheel cylinder or a cylinder of a caliper which is configured to perform a braking operation by holding a brake drum of a wheel using hydraulic pressure provided from the master cylinder.
When the driver manipulates the brake pedal while driving the vehicle, the booster amplifies the brake pedal manipulating force, and the master cylinder generates hydraulic pressure using the amplified force. The generated hydraulic pressure is applied to the wheel cylinder or the cylinder of the caliper. Thereby, braking force is applied to the wheel by a piston operation of the wheel cylinder or the cylinder of the caliper.
With regard to detailed configuration of the conventional master cylinder, a rod is coupled to a piston in a bolt coupling manner. Here, a separate component such as a washer unit is needed to reinforce the coupling force between the rod and the piston and reduce the friction therebetween. Hence, there is a problem in that the number of parts and the production cost are increased.
On the one hand, a spring assembly formed of a piston, a rod, a spring, a stopper, etc. is installed in the master cylinder to prevent a hydraulic pressure deviation and determine an advancing distance of the piston required to generate a hydraulic pressure.
Here, a problem arises in that, when the spring is compressed by advancing the piston of the spring assembly, the rod functioning as a guide may wobble and thus buckle, and scratches and noises may be continuously generated by contact between the spring and the inner circumferential surface of the piston.
Furthermore, the conventional art is problematic in that the number of parts constituting the spring assembly is relatively large, and an assembly process is complex, whereby the production cost is increased.
The related art of the present invention is disclosed in Korean Patent Unexamined Publication No. 10-2012-0003299 (published on Jan. 10, 2012 and entitled “Plunger master cylinder for brake”).